Learning to really see again,

I tried to do a likeness of a gorgeous hip hop model (Tomika Skanes) as a test to see if I have problems with my skill or my eye.  What I found out is that I really do not take the time to really see what I am looking at.  As an comic artist we are told to accentuate, spin and revise on what we know.  But our first step should be to see then do the rest. So, I decided to cheat by just tracing the hard lines and place the image side by side to my drawing and see if I could copy the rendering of tones.  My first realization is that it is not line that defines the face.  It is tone and the direction of shading flow and placement of darks that drives the form.  I learned I am getting better with my rendering but have a long way to go to identify placement of high lights and shadow to render form and ultimately catch character.  I found out that painters figured it out that layers of various tones  builds a face up- even in monochromatic fashion.  As an artist I tend to see in toon-shading with 2-4 variations of tone and the human face has at least 8 if not more combinations to achieve form- Ie I need to re-assess how I look at things and not be so lazy to capture....My big future challenge now is to accurately render shapes in proper proportion and angle.. I had to keep tweeking the eyes to make them stare into the camera and even now it looks funny- oh well- have to keep working